|Try to repair the partition on the flash drive by using a utility called testdisk. Be sure to read all the insturtions before using it. Get testdisk at the link below. |
Most problems with data corruption on external storage devices are caused by improper removal. You should always use the safely remove icon in the tray by the clock before removing a USB storage device.
As was stated above. it is foolish to rely on only one copy of important files.